1. Field of the Invention
The present invention relates generally to a positioning device, and more particularly to a positioning device used in antenna's testing system.
2. Description of the Prior Art
An antenna's testing system is used to test antenna's radiance for judge if the antenna meets the demand. A 3D graphic showed the antenna's working field form and a gain of the antenna are both important parameter showed the antenna's radiance. And the 3D graphic is produced by a 3D testing system working in a anechoic chamber. The 3D testing system generally includes an antenna under test, a rotatable support, a testing antenna and a crane supporting the testing antenna. The crane provides a position to the testing antenna to make the testing antenna aimed for the antenna under test.
Referencing to FIG. 1, a prior antenna's testing system A is shown. The system A includes an under-test antenna B, a rotatable support C to support the under-test antenna B, a testing antenna D, a crane E and a control system F. When the under-test antenna B is tested, the testing antenna D is adjusted to located on a height and to be aimed to the under-test antenna B. However, the testing system A fails to equip a calibrating equipment, and thus, the testing antenna D is helluva to be exactly aimed to the under-testing antenna.
Hence, in this art, a positing device to overcome the above-mentioned disadvantages of the prior art should be provided.